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A package performance bottleneck is developing because of the inability to densely wire single chip modules together on the printed wiring board. An array processor, constructed by means of various high performance packaging techniques, demonstrates that multichip modules of even modest size can give dramatic improvements in the packaging figure of merit.

The evolution of today's high speed electronic systems has resulted in the need for modules which are able to provide all chip‐to‐chip interconnection with very fine top level and buried conductor traces, and a dielectric with a very dense via grid pattern. As standard thick film technology is capable of pitches only down to 250 µm, new photoimageable thick film pastes have been developed in order to achieve a higher resolution. These materials allow one to combine the advantages of screen printing as a deposition technique with photolithography for the patterning. The image is produced by exposing the printed paste through a photomask to define either lines or vias, so that a very high resolution (50 (µm pitch), similar to that available in MCM‐D or MCM‐L, can be achieved. This paper describes the processing of the photoimageable dielectric and conductor pastes. As an example of the capability of this technology, a module for electro‐optical interconnection is presented.

Laminated substrates are used widely in the manufacture of multichip modules (MCM‐L) by the electronic packaging industry. Of late, the thrust has been towards higher density circuitry to achieve improved performance and reduced size. This has led to the use of finer lines and spacings, smaller drilled holes and buried vias in organic laminates leading to reliability issues such as electrochemical migration. One of the forms of electrochemical migration is known as conductive filament formation. Conductive filament formation is an electrochemical process. In accelerated environments of temperature and humidity, organic laminates can develop a loss of insulation resistance between conductors, eventually resulting in loss of electrical function of the circuit. The paper aims at discussing electrochemical migration in general, and conductive filament formation in particular, and its impact on the reliability of MCM‐L.

This event, the first sponsored by ISHM, takes place in Pardubice on the 19–20 November 1991. Pardubice is a town of some 100,000 inhabitants about 60 miles east of Prague. A welcome is extended to all ISHM Chapter members.

As speed and complexity of electronic systems increase, the interconnect density has become the critical limitation to the performance of electrical systems. The performance of computing and switching systems can be increased by optimizing the interconnect density and throughput. At the board to board level, electrical interconnects at high speeds require a bulky and expensive backplane. At the chip to chip area, the allocation of interconnects limits the performance of the chips. Electrical lossy lines limit the maximum interconnect distance due to reflections, risetime degradation, increased delay, attenuation and cross talk . Optical interconnects present the possibility of solving the interconnect problems by potentially achieving a high bandwidth and high volume density of channels. At high data rates (greater than 1 Gb/s) several channels may operate with negligible mutual interference.

A one‐day Technical Symposium on Printed Circuits will be held at the Swan Diplomat Hotel at Streatley on Thames, Berkshire, on Thursday 29 March 1990.

High performance aluminium nitride water cooled heat sinks were fabricated and characterized. A variety of fabrication processes were employed to meet different cooling requirements. They include laser cut microchannel coolers for chip and multichip heat sinks as well as dry pressed pin fin heat sinks for power electronics. Thermal simulation was used to optimize the heat sink design.

Following the discussion at our recent Annual General Meeting, a questionnaire was sent out to all members. Almost half of them replied despite the fact that the time allowed for returning the questionnaire had been kept very short. Some members even provided detailed comments.

Dates: 29–31 May 1991 Venue: De Doelen Conference Centre, Rotterdam, The Netherlands The Benelux Chapter of the International Society for Hybrid Microelectronics will be organising the 8th European Microelectronics Conference. The event will take place at ‘De Doelen’, Rotterdam, The Netherlands, from 29 to 31 May 1991.

National Starch and Chemical Corporation have announced the appointment of Graham Jones as sales manager, Electronic Materials and Adhesives (EM&A), Europe, headquartered at National's subsidiary in Slough, England. Mr Jones will report to Martin M. Grover, divisional vice president, EM&A, in Bridgewater, NJ.